This clever loop transforms a humble pump spell into a self-sustaining engine by turning the stack and the graveyard into a revolving door for your spellcasters. When you cast Presumed Dead and follow it with Naru Meha, Master Wizard, her enter-the-battlefield trigger copies the instant to target herself, granting her a delayed revival trigger when she eventually perishes. That's where Phyrexian Altar earns its keep, allowing you to instantly sacrifice Naru Meha for any color of mana before the resolution of her own copied protection. Because Presumed Dead's effect brings her right back to the battlefield—where she immediately triggers to copy the original spell once more—you can repeat this sacrifice-and-return cycle indefinitely to generate infinite colored mana and an endless stream of death, sacrifice, and entry triggers.